JPH03248662A - Feeder circuit - Google Patents
Feeder circuitInfo
- Publication number
- JPH03248662A JPH03248662A JP2046385A JP4638590A JPH03248662A JP H03248662 A JPH03248662 A JP H03248662A JP 2046385 A JP2046385 A JP 2046385A JP 4638590 A JP4638590 A JP 4638590A JP H03248662 A JPH03248662 A JP H03248662A
- Authority
- JP
- Japan
- Prior art keywords
- transistor
- zener diode
- base
- signal line
- power supply
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 230000005236 sound signal Effects 0.000 claims abstract description 29
- 230000001105 regulatory effect Effects 0.000 claims description 3
- 239000003990 capacitor Substances 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 1
- 230000011664 signaling Effects 0.000 description 1
Landscapes
- Time-Division Multiplex Systems (AREA)
- Devices For Supply Of Signal Current (AREA)
Abstract
Description
【発明の詳細な説明】
〔概要〕
音声信号を伝送する信号線に給電を行なう給電回路に関
し、
給電の有無に拘らず音声信号を漏失することのないこと
を目的とし、
音声信号を伝送する信号線に所定電圧が印加されたとき
、この所定電圧を第１のツェナーダイオードで定電圧化
してトランジスタのベース・エミッタ間に印加し該トラ
ンジスタにより該信号線に定電流の給電を行なう給電回
路において、該信号線に所定電圧が印加されないとき該
信号線を伝送される音声信号による該トランジスタの導
通防止用として該トランジスタのベースに第２のツェナ
ーダイオードを接続して構成する。[Detailed Description of the Invention] [Summary] Regarding a power supply circuit that supplies power to a signal line that transmits an audio signal, the purpose is to prevent audio signals from leaking regardless of the presence or absence of power supply, and to provide a signal that transmits an audio signal. In a power supply circuit, when a predetermined voltage is applied to a line, the predetermined voltage is regulated by a first Zener diode and applied between the base and emitter of a transistor, and the transistor supplies a constant current to the signal line, A second Zener diode is connected to the base of the transistor to prevent conduction of the transistor due to an audio signal transmitted through the signal line when a predetermined voltage is not applied to the signal line.
本発明は給電回路に関し、音声信号を伝送する信号線に
給電を行なう給電回路に関する。The present invention relates to a power supply circuit, and more particularly, to a power supply circuit that supplies power to a signal line that transmits an audio signal.
ＰＣＭ１次群伝送端局装置では第２図に示す如く、交換
ｔａ１０とチャンネルユニット１１との開信号線１２ａ
、１２ｂで接続され、このようなチャンネルユニットが
複数ユニット多重化装置に接続されている。In the PCM primary group transmission terminal equipment, as shown in FIG.
, 12b, and such channel units are connected to a multiple unit multiplexer.
チャンネルユニット１１内の給電回路１４ａは従来、第
３図に示す如くコイルＬ１と抵抗Ｒ１とで構成し、交換
機１０内のリレースイッチ１５ａ。Conventionally, the power supply circuit 14a in the channel unit 11 includes a coil L1 and a resistor R1 as shown in FIG. 3, and a relay switch 15a in the exchange 10.
１５ｂ夫々が閉成したとき、直流電源（例えば−６０Ｖ
）１６ａ、１６ｂによる電流を流して、端子１７ａ、１
７ｂより入来する音声信号の直流バイアスを行なってＳ
／Ｎ比を向上させている。When each 15b is closed, the DC power supply (e.g. -60V
) 16a, 16b, the terminals 17a, 1
DC bias is applied to the audio signal coming from 7b
/N ratio is improved.
近年、装置の小型化及びコストダウン化に伴ない従来の
給電回路は第４図に示す回路構成とされている。In recent years, with the miniaturization and cost reduction of devices, a conventional power supply circuit has a circuit configuration shown in FIG.
同図中、給Ｉｆ回路２０はスイッチ１５ａの閉成時にツ
ェナーダイオードＤｚ＋によってトランジスタＴ’ｒ１
のベース・エミッタ間電圧が例えば１０Ｖ程度とされ、
トランジスタＴｒ１が導通して定電流の給電を行なう。In the figure, the supply If circuit 20 is connected to the transistor T'r1 by the Zener diode Dz+ when the switch 15a is closed.
For example, the base-emitter voltage of is about 10V,
Transistor Tr1 conducts and supplies constant current.
この給電回路２０は音声信号周波数に対するインピーダ
ンスが高く、音声信号はコンデンサＣ１よりチャンネル
ユニット１１の音声トランスＴ１に供給される。なお、
コンデンサＣ２は音声信号によりトランジスタＴｒ１の
ベース・エミッタ間電圧が変動するのを防止しており、
抵抗Ｒ２はバイアス抵抗である。This power supply circuit 20 has a high impedance with respect to the audio signal frequency, and the audio signal is supplied to the audio transformer T1 of the channel unit 11 from the capacitor C1. In addition,
The capacitor C2 prevents the base-emitter voltage of the transistor Tr1 from changing due to the audio signal.
Resistor R2 is a bias resistor.
リレースイッチ１５ａ、１５ｂを閉成して給電回路が給
電を行なっているときだけ音声信号が交換機１０より信
号線１２ａ、１２ｂに供給される通常の信号方式では給
電回路２０を用いて何ら問題はない。There is no problem with using the power supply circuit 20 in the normal signaling system in which the voice signal is supplied from the exchange 10 to the signal lines 12a, 12b only when the relay switches 15a, 15b are closed and the power supply circuit is supplying power. .
しかし、給電時は勿論、リレースイッチ１５ａ。However, when power is supplied, of course, the relay switch 15a is used.
１５ｂを開成して給電回路２０が給電を行なってないと
きにも音声信号が交換機１０より信号線１２ａ、１２ｂ
に供給される特殊な信号方式では給電回路２０を用いる
と音声信号が一部失われてしまう。15b is open and the power supply circuit 20 is not supplying power, audio signals are transmitted from the exchange 10 to the signal lines 12a and 12b.
In the case of a special signal system that is supplied to a computer, if the power supply circuit 20 is used, part of the audio signal will be lost.
例えば音声信号レベルがトランジスタＴｒｌの閾値を越
える一１ｖ程度となると、給電回路２０のトランジスタ
７−ｒｌが導通してしまい、音声信号が失われてコンデ
ンサＣＩより音声トランスＴ１に供給されないという問
題がある。For example, when the audio signal level exceeds the threshold of the transistor Trl by about 1 V, the transistor 7-rl of the power supply circuit 20 becomes conductive, causing the problem that the audio signal is lost and is not supplied from the capacitor CI to the audio transformer T1. .
本発明は上記の点に鑑みなされたもので、給電の有無に
拘らず音声信号を漏失することのない給電回路を提供す
ることを目的とあった。The present invention was made in view of the above points, and an object of the present invention is to provide a power supply circuit that does not leak audio signals regardless of whether or not power is supplied.
本発明の給電回路は、
音声信号を伝送する信号線に所定電圧が印加されたとき
、この所定電圧を第１のツェナーダイオードで定電圧化
してトランジスタのベース・エミッタ間に印加しトラン
ジスタにより信号線に定電流の給電を行なう給電口路に
おいて、
信号線に所定電圧が印加されないとき信号線を伝送され
る音声信号によるトランジスタの導通防止用として該ト
ランジスタのベースに第２のツェナーダイオードを接続
してなる。In the power supply circuit of the present invention, when a predetermined voltage is applied to a signal line that transmits an audio signal, this predetermined voltage is regulated by the first Zener diode and applied between the base and emitter of a transistor, and the signal line is connected by the transistor. A second Zener diode is connected to the base of the transistor in order to prevent the transistor from becoming conductive due to the audio signal transmitted through the signal line when a predetermined voltage is not applied to the signal line in the power supply path that supplies constant current to the signal line. Become.
本発明においては給電を行なわないときの音声信号の振
幅が大となっても、第２のツェナーダイオードによって
トランジスタのベース・エミッタ間電圧がトランジスタ
の閾値を越えることがなく、トランジスタは導通しない
。これによって非給電時の音声信号が給電回路から漏失
することが防止される。In the present invention, even if the amplitude of the audio signal becomes large when no power is being supplied, the second Zener diode prevents the base-emitter voltage of the transistor from exceeding the threshold of the transistor, and the transistor does not conduct. This prevents audio signals from leaking from the power supply circuit when power is not supplied.
第１図は本発明回路の一実施例の回路図を示す。 FIG. 1 shows a circuit diagram of an embodiment of the circuit of the present invention.
同図中、第４図と同一部分には同一符号を付し、その説
明を省略する。In this figure, the same parts as in FIG. 4 are given the same reference numerals, and their explanations will be omitted.
第１図において、給電回路３０を構成するＰＮＰ形トラ
ンジスタＴｒ１はコレクタを信号線１２ａに接続され、
エミッタを接地されでいる。トランジスタＴｒｌのベー
スには例えばツェナー電圧的３Ｖのツェナーダイオード
０２２のカソードが接続され、トランジスタ丁ｒ１のコ
レクタとツェナーダイオードＤＺ２のアノードとの間に
はバイアス用の抵抗Ｒ２が接続されている。またトラン
ジスタＴｒｉのエミッタには例えばツェナー電圧的９ｖ
のツェナーダイオードＤＺ３のカソードが接続され、ツ
ェナーダイオードＤＺ３のアノードはツェナーダイオー
ドＤＺ２のアノードに接続されている。In FIG. 1, a PNP transistor Tr1 constituting the power supply circuit 30 has its collector connected to the signal line 12a,
The emitter is grounded. For example, the cathode of a Zener diode 022 having a Zener voltage of 3V is connected to the base of the transistor Trl, and a bias resistor R2 is connected between the collector of the transistor R1 and the anode of the Zener diode DZ2. Also, the emitter of the transistor Tri has a Zener voltage of 9V, for example.
The cathode of the Zener diode DZ3 is connected to the Zener diode DZ3, and the anode of the Zener diode DZ3 is connected to the anode of the Zener diode DZ2.
更にツェナーダイオードＤ２３と並列にコンデンサＣ２
が接続されている。Furthermore, a capacitor C2 is connected in parallel with the Zener diode D23.
is connected.
ここで、第１図に示すリレースイッチ１５ａ。Here, the relay switch 15a shown in FIG.
１５ｂを閉成しているときにはツェナーダイオードＤＺ
３及びＤ２２のツェナー電圧によってトランジスタＴｒ
ｌのベース・エミッタ間電圧は１２Ｖ程度とされトラン
ジスタＴｒ１が導通して定電流回路３０は定電流の給電
を行なう。When 15b is closed, the Zener diode DZ
The transistor Tr
The base-emitter voltage of transistor Tr1 is approximately 12V, transistor Tr1 is turned on, and constant current circuit 30 supplies constant current.
また、リレースイッチ１５ａ、１５ｂを開成して供給回
路３０が給電を行なわないとき音声信号が供給され、こ
の音声信号レベルが一３ｖ程度となってもツェナーダイ
オードＤＺ２が設けられているためにトランジスタＴｒ
１のベース・エミッタ問電圧はトランジスタ７ｒ１の閾
値（例えば０．７Ｖ）を越えることがなくトランジスタ
Ｔｒ１は導通することがない。音声信号が供給されなけ
ればトランジスタＴｒ１が導通しないことは勿論である
。Further, when the relay switches 15a and 15b are opened and the supply circuit 30 does not supply power, an audio signal is supplied, and even if the audio signal level reaches about 13V, the transistor Tr is provided with the Zener diode DZ2.
The base-emitter voltage of the transistor Tr1 does not exceed the threshold value (for example, 0.7 V) of the transistor 7r1, and the transistor Tr1 does not become conductive. Of course, the transistor Tr1 does not conduct unless the audio signal is supplied.
このように非給電時にトランジスタＴｒ１が導通しない
ため、信号線１２ａを伝送された音声信号が給電回路３
０から漏失することが防止され、音声信号は全て第２図
に示す音声トランスＴ＋に供給される。In this way, since the transistor Tr1 does not conduct when power is not supplied, the audio signal transmitted through the signal line 12a is transmitted to the power supply circuit 3.
0 and all audio signals are fed to the audio transformer T+ shown in FIG.
上述の如く、本発明になる給電回路によれば、給電の有
無に拘らず音声信号を漏失することがなく、かつ回路の
小型化及びコストダウン化を行なうことができ、実用上
きわめて有用である。As described above, the power supply circuit of the present invention does not leak audio signals regardless of whether or not power is supplied, and the circuit can be miniaturized and cost reduced, and is extremely useful in practice. .
第１図は本発明回路の一実施例の回路図、第２図は端局
装置の構成を示す図、
第３図、第４図夫々は従来回路の回路図である６図にお
いて、
１０は交換機、
１１はチャンネルユニット、
１２ａ、１２ｂは信号線、
Ｃ２はコンデンサ、
ＤＺ２．ＤＺ３はツェナーダイオード、Ｒ２は抵抗、
Ｔｒｌはトランジスタ
を示す。FIG. 1 is a circuit diagram of an embodiment of the circuit of the present invention, FIG. 2 is a diagram showing the configuration of a terminal equipment, and FIGS. 3 and 4 are circuit diagrams of conventional circuits. Exchanger, 11 is a channel unit, 12a, 12b are signal lines, C2 is a capacitor, DZ2. DZ3 is a Zener diode, R2 is a resistor, and Trl is a transistor.
Claims (1)
されたとき、この所定電圧を第１のツェナーダイオード
（Ｄｚ＿３）で定電圧化してトランジスタ（Ｔｒ１）の
ベース・エミッタ間に印加し該トランジスタ（Ｔｒ１）
により該信号線（１２ａ）に定電流の給電を行なう給電
回路において、該信号線（１２ａ）に所定電圧が印加さ
れないとき該信号線（１２ａ）を伝送される音声信号に
よる該トランジスタ（Ｔｒ１）の導通防止用として該ト
ランジスタ（Ｔｒ１）のベースに第２のツェナーダイオ
ード（Ｄｚ＿２）を接続してなることを特徴とする給電
回路。When a predetermined voltage is applied to the signal line (12a) that transmits an audio signal, this predetermined voltage is regulated by the first Zener diode (Dz_3) and applied between the base and emitter of the transistor (Tr1). (Tr1)
In a power supply circuit that supplies a constant current to the signal line (12a), when a predetermined voltage is not applied to the signal line (12a), the transistor (Tr1) is activated by an audio signal transmitted through the signal line (12a). A power supply circuit characterized in that a second Zener diode (Dz_2) is connected to the base of the transistor (Tr1) to prevent conduction.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2046385A JP2656131B2 (en) | 1990-02-27 | 1990-02-27 | Power supply circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2046385A JP2656131B2 (en) | 1990-02-27 | 1990-02-27 | Power supply circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH03248662A true JPH03248662A (en) | 1991-11-06 |
| JP2656131B2 JP2656131B2 (en) | 1997-09-24 |
Family
ID=12745673
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2046385A Expired - Fee Related JP2656131B2 (en) | 1990-02-27 | 1990-02-27 | Power supply circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2656131B2 (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61199397A (en) * | 1985-02-28 | 1986-09-03 | Nec Corp | Loop circuit for channel |
-
1990
- 1990-02-27 JP JP2046385A patent/JP2656131B2/en not_active Expired - Fee Related
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61199397A (en) * | 1985-02-28 | 1986-09-03 | Nec Corp | Loop circuit for channel |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2656131B2 (en) | 1997-09-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4444999A (en) | Automatic electronic disconnector for subscriber terminal equipment | |
| US3141068A (en) | Robert t | |
| US3772470A (en) | Threshold circuit for tone-ringer | |
| US4115660A (en) | Telephone line interfacing circuit with directional transfer of ringing current and off-hook indications | |
| JPH03248662A (en) | Feeder circuit | |
| US4063045A (en) | Telecommunication line switching circuit | |
| CA2117648C (en) | Circuitry for superimposing small, low energy signals and large, essentially higher energy signals | |
| EP0425675B1 (en) | Ground fault detecting circuit for subscriber lines | |
| US4964026A (en) | Noise reduction technique for PWM controllers | |
| US4185173A (en) | Key telephone call signalling circuit | |
| US4476351A (en) | Subscriber loop current regulator | |
| EP0713320B1 (en) | Ring generator circuit | |
| US3941941A (en) | Relayless switching circuit for application of ringing signals | |
| GB2070370A (en) | Amplifier protection | |
| WO1983001355A1 (en) | Detector circuit for communication lines | |
| KR910001680B1 (en) | Doorphone interface circuit | |
| US4388497A (en) | Telephone power supply arrangement | |
| US4935957A (en) | Key telephone system | |
| US4021621A (en) | Automatic group exclusion circuit for a key telephone system | |
| US3478175A (en) | Direct current signal receiver | |
| KR890700291A (en) | Power supply for loudspeaker, which supplies power to the amplifier connected to the speaker | |
| BE1007208A3 (en) | Telecommunications system equipped with a supply switch for a telecommunication line and a supply switch for a telecommunication line suitable for application in the telecommunication system | |
| KR100232725B1 (en) | Loop dialing circuit in key-phone system | |
| JP2959180B2 (en) | Power supply line switching circuit | |
| JPS5853539B2 (en) | Bunpaiki |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |